Journal of Clinical and Hospital Pharmacy (1982) 7,71-73.

SHORT COMMUNICATION

ADVERSE DRUG REACTION MONITORING BY WARD PHARMACISTS*

C. Hardman and B. Lloyd

Drug Informanon h e , Lincoln County Hospud, Lincoln

SUMMARY

An investigation into adverse reactions to drugs arising in a hospital over a 5 week period is described and the role of the ward pharmacist in detecting and reporting those reactions discussed. Sources of information avadable to confirm a diagnosis of ‘adverse drug reaction’ are described and the problem of establishing clinical significance examined.

I N T R O D U C T I O N

Adverse drug reactions have been widely studied in recent years, and the consequences of iatrogenic disease, initially not linked with the use of a particular drug, is well illustrated by the problems associated with thalidomide and practolol in recent years. There are many reports in the literature on the frequency and consequences of adverse drug reactions, frequently in hospital patients but also occasionally from the community. Some studies are on a large scale and of a long-term nature, e.g. the Boston Collaborative Drug Surveillance Programme, but most have concentrated on individual hospitals or groups of drugs.

The various methods for detecting and reporting these reactions have also been well described. In the U.K. the responsible body for collecting information on adverse reactions is the Commitree on Safety of Medicines and the reporting method most widely used is the yellow card system of pre-paid, addressed sheets on which the reporting doctors supplies basic information about the case. This is entirely voluntary but the CSM make a special request for new drugs to be monitored closely. Although the CSM will accept reports only from doctors and dentists there are many local schemes where pharmacists are actively working with medical and dental staff in the preparation and storage of adverse reaction reports. At hospital level we believe it to be both practical and desirable to involve ward pharmacists in detecting and encouraging the reporting of reactions. This project was designed to assess the viability of this premise.

M E T H O D

All the acute wards in the hospital (300 beds approximately) were visited daily during the

‘Paper presented at the European Society of Clinical Pharmacy Workshop-Gatwick, March 1981. Mectlng organized by Dr S. Ellis and Mr C. W. Barrett.

0143-3 180/82/03CKMO71 SO2.00 Q 1982 Blackwell Scientific Publications

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72 C. Hardman and B. U o y d

study period of 5 weeks. Prescriptions were reviewed, as in our standard ward pharmacy visits, to check for apparent adverse reactions indicated by the prescription of drugs likely to be for the relief of symptoms associated with a reaction, or those which would directly counteract a reaction. This was confirmed by discussion with the ward staff or by checking the patient’s notes for confirmation of the diagnosis. Where a reaction was suspected but had not yet been diagnosed as such, then evidence was sought to support the suspicion before bringing it to the notice of medical staf€. Such evidence might include laboratory data from the patient’s notes or anecdotal observations from the nursing staff. Many reactions were found in this way where the nurses had noted some alteration in the patient’s condition but had not associated it with drug therapy. Where necessary, further support was sought from a search of standard literature sources in the hospital Drug Information Centre to confirm that an association between drug and reaction was probable. Where a previously unreported reaction or rarely occurring reaction was suspected then a full evaluation was undertaken before advising medical staff.

The survey was undertaken to detect any reaction, including those which are commonly accepted as minor problems and generally are not considered further. Examples in this category include simple gastro-intestinal and central nervous system complaints. There is, of course, an element of risk in linking these relatively simple problems with a particular drug and therefore a suitable confirmation, either by a time association or a rechallenge, was sought before including the reaction in the results. Because of this well-recognized problem of doubt existing as to the positive association in some cases, we adopted the West Midlands system (1) of classifying reactions into one of the four grades. Their frequency during the study period were: Class 1, definite (71%); Class 2, probable (9.7%); Class 3, doubtful (12.9%); Class 4, unlikely (6.4%).

R E S U L T S Table 1 illustrates the reactions detected or reported and their classification. Differences in

Table 1. CIY&tion of adverse reactions reported

Drug Frequency Reaction Class

Lugol’r iodine Allopurinol Diamorphine Phenyroin Phenyroin DiBunisal Lidotlazinc Disop yramide Diamorphine Paracetmol Magnesium hydroxide Cvbenoxolone Fruscmide Bendrofluaride Metoclopramide Cotrimoxazole Mctronidazole Magnapen

I 1 I I I 1 I 3 2 1 1 I

12 2 I I 1 I

Hypersensitivity Skin rash Constipation Toxicity Toxicity G - I bleeding Ventricular fibrillation Digoxio Inreraction Constipation Raised liver enzymes (OD) Diarrhoea Hypokalacmia H ypokalaemia Hypokalaerma Extra pyramidal reaction Skin rash Oral reaction Skin rash

2 I 3 3 4 3 4 3 1 I I 2 I I I I 2 I

Drug reaction monitoring 73

class between identical drugs and reactions are a reflection of variations in certainty in individual cases. The high number of hypokalaemia episodes with diuretics may be accounted for by our taking small drops in serum potassium as evidence, even though these may not have been clinically significant. Of the reactions detected one was considered to be suitable for reporting to the Committee on Safety of Medicines.

DISCUSSION This project has illustrated that ward pharmacists have in active role to play in adverse drug reaction monitoring. Many of the reactions described in the results would have passed undetected had they not been brought to the attention of riiedical staff by the ward pharmacist and, whilst they may not have been important clinically in terms of the manage- ment of the patient’s disease, they certainly had an effect on the patient’s comfort and general condition after the reaction had been resolved. In all of those cases where an effect on the management of the patient was involved, the case was discussed between ourselves before approaching the clinician in charge of the case.

The project has also shown the willingness of medical and nursing staff to become involved in the problems of adverse reactions and illustrated the ease with which co-operation can be reached between the professions. It is important to support and maintain this co-operation by active follow-up in the form of additional information on the particular reaction reported.

REFERENCE

I . Becky, L. (ed) (1975) Bulletln of the West Midlands Adverse Drug Reaction Group, No 1